title: Trehalose biosynthesis in Myxococcus xanthus under osmotic stress and during spore formation.
abstract: In Myxococcus xanthus, trehalose is synthesized in response to osmotic stress and during spore formation. Genome data analysis indicated that M. xanthus has five related enzymes involved in four trehalose synthesis pathways (OtsAB, TreYZ, TreT and TreS). Under osmotic conditions, the amount of trehalose in wild-type cells was increased quickly by the OtsAB pathway, and the otsAB mutant began to synthesize trehalose using the TreYZ pathway. Also, in comparison with the wild-type strain, the otsAB and treZ mutants showed ∼65% and 40% reductions in the levels of intracellular trehalose accumulation, respectively, after 42 h of treatment with NaCl. In starvation-induced development of the wild-type strain, OtsAB activity was detected at middle and late stages of fruiting body development, and TreYZ activity was also detected at a late stage of development. Accumulation levels of trehalose in otsAB and treZ mutants were ∼30% and 65% of that of the wild-type strain after 7 days of development, respectively. Wild-type and mutant strains did not show TreT and TreS activities under osmotic stress and development conditions. These results suggested that the OtsAB pathway may play a major role in trehalose biosynthesis in M. xanthus cells, with the TreYZ pathway playing an auxiliary role.
authors.affiliation: Department of Applied Biological Science, Faculty of Agriculture, Kagawa University, Miki-cho, Kagawa 761-0795, Japan.
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Kimura
authors.forename: Shinji
authors.initials: S
authors.lastname: Kawasaki
authors.forename: Ryouta
authors.initials: R
authors.lastname: Tuchimoto
authors.forename: Naotaka
authors.initials: N
authors.lastname: Tanaka
mesh_terms: D001483:Base Sequence; D002855:Chromatography, Thin Layer; D017931:DNA Primers; D016941:Myxococcus xanthus / Q000378:metabolism*; D009997:Osmotic Pressure; D013171:Spores, Bacterial / Q000254:growth & development*; D014199:Trehalose / Q000096:biosynthesis*
chemical_list: D017931:DNA Primers; D014199:Trehalose
keywords: Myxococcus xanthus; carbohyrate; enzymatic kinetics; osmotic stress; trehalose